Heat treatment of filaments



H. WHITTAKER ETAL 3,387,833

HEAT TREATMENT OF FILAMENTS June 11, 1968 2 Sheets-Sheet 1 Filed Sept. 2, 1966 June 1968 H. WHITTAKER ETAL 3,387,833

HEAT TREATMENT OF FILAME NTS Filed Sept. 2, 1966 2 Sheets-Sheet 2 United States Patent 3,387,833 HEAT TREATMENT OF FILAMENTS Harold Whittaker, Alkrington, Middleton, and Anthony James Booth, Helmshore, Rossendale, England, as-

signors to T.M.M. (Research) Limited, Oldham,

Lancashire, England, a British company Filed Sept. 2, 1966, Ser. No. 576,913 9 Claims. (Cl. 263-3) ABSTRACT OF THE DISCLOSURE Apparatus for heat treating crimped yarn or filament. The apparatus includes a pair of rollers around which the yarn or filament is guided in a series of loops with these rollers having a feed end for receiving the first filament loop and a delivery end from which the last loop is delivered. Between their feed and delivery ends the rollers are at least in part of a tapered configuration so that the crimped yarn can progressively relax without any substantial reduction in the amount of crimp while the yarn is on the tapered roller portions. The heat treatment is derived from a heating means mounted between the rollers and within the series of filament loops with this heating means having opposed heating surfaces situated in the path of movement of the filament loops so that the series of loops will first engage one heating surface on one side of the heating means and will then engage the second heating surface on the other side of the heating means.

This invention relates to the heat treatment of filaments and in particular to the heat treatment of travelling synthetic filaments.

According to the present invention, there is provided apparatus for heat treating a travelling filament or yarn, comprising two spaced driven rollers about which the filament to be treated is passed to form a succession of filament loops round the two rollers, and heating means for heating said filament loops during passage of the filament from one roller to the other, the arrangement being such that the path length of the filament loop at the feed end of the rollers is greater than the path length of the filament loop at the delivery end thereof.

Preferably, the heating means comprises a heating device mounted between the rollers and within the filament loops and so arranged that the portions of the filament loops extending between the rollers on one side thereof contact a heating surface on one side of the device and the portions of the filament loops extending between the rollers on the other side thereof contact a heating surface on the other side of the device,

In order to ensure adequate spacing of the filament loops along the rollers, in a preferred embodiment of the invention one of the rollers is inclined to the other roller in such a manner that the axis of the inclined roller is angularly displaced in a plane perpendicular to a normal to the axis of the other roller.

Furthermore, each roller is preferably provided with a frusto-conical portion located at or towards the feed end theref and the roller may be cylindrical at or towards the delivery end, the arrangement being such that the diameter of the roller decreases in a direction from the feed end to the delivery end thereof. The frusto-conical portion of the roller may be provided in the surface thereof with a plurality of annular grooves which are adapted to accommodate the filament loops. The cylindrical delivery end of the roller may also be provided with a plurality of annular grooves.

Some embodiments of the invention will now be deice scribed by way of example with reference to the accompanying drawings in which:

FIG. 1 is a side elevation of apparatus according to a first embodiment of the invention,

FIG. 2 is a sectional end view of the apparatus shown in FIG. 1, taken on the line IIII in FIG. 1,

FIG. 3 is a schematic plan view of the apparatus shown in FIG. 1, illustrating the inclination of the axes of the two rollers,

FIGS. 4, 5 and 6 are side elevations of three alternative forms of roller for use in the apparatus shown in FIG. 1.

Referring first to FIGS. 1 and 2, a pair of vertically spaced filament advancing rollers 11 and 12 are arranged at opposite ends of a heater plate 13 and adapted to be driven in the same sense and at the same speed by a driving arrangement comprising a driving belt 14 driven by an electric motor and drivingly engaging a belt pulley 15 fixed on a roller supporting shaft 16 of the roller 12, and an endless belt 17 passing round the pulley 15 and drivingly engaging a pulley 18 carried on a shaft 19 of the roller 11. As shown, each of the rollers 11 and 12 comprises a frusto-conical portion 20 and a cylindrical portion 21 and the heater plate 13 is recessed and cutaway at each end to conform to and accommodate the roller.

A filament 22 from a crimping stuffer box (not shown) is fed at low tension through eyelets 23 and 24, from the latter of which it passes round the underside of the roller 12 and then upwards to the other side of the roller 11 over which it passes. The filament 22 then passes down again to the lower roller 12 and then commences to form in succession a plurality of loops round the two rollers 11 and 12, finally leaving the rollers in.a downward direction through a filament eyelet 25. It will be seen that the heater plate 13- extends to the full length of the rollers 11 and 12 and is provided with side heating surfaces over which the filament is caused to ride in its passage from one roller to the other.

As shown in FIG. 3, the rollers 11 and 12 are inclined to each other, the axis of the roller 11 being angularly displaced in a horizontal plane in one sense in relation to the vertical medial plane through the heater plate 13 and the axis of the roller 12 being angularly displaced in a horizontal plane in the opposite sense.

In operation, filament to be heat treated is passed in a plurality of loops about the rollers 11 and 12 as illustrated in FIG. 1 so that the filament makes contact with the two sides of the heater plate 13 as it passes from one roller to the other. By providing a frusto-conical portion 20 on each of the rollers 11 and 12 the path followed by each successive loop about the frusto-conical portions decreases in length as the centre of the rollers is approached and thereafter remains constant along the cylindrical portions 21 thereof.

The filament fed to the feed end of the first roller 11 is in a highly crimped condition and when heated by passing in contact with the heating surfaces of the heater plate 13 tends to contract. Unless provision is made for allowing contraction to take place the amount of crimp in the filament will be reduced. The frusto-conical portions 20 of the rollers 11 and 12 allow progressive relaxation of the filament 22. without reduction of the amount of crimp or at least with a controlled reduction of the amount of crimp in the filament. Heat setting of the crimp is then effected on the cylindrical portions of the rollers and the crimped heat-set filaments are finally delivered from the cylindrical ends of the rollers 11 and 12.

In an alternative embodiment of the invention, in which setting of the crimped filament is not required, each of the rollers 11 and 12 may be replaced by rollers which are of frusto-conical form throughout their length and which taper from the feed end towards the delivery end as shown in FIG. 4, relaxation of the filament taking place steadily as the filament passes, in loops, from the feed end to the delivery end.

In yet another embodiment of the invention, each of the rollers 11 and 12 is replaced by a roller of the form shown in FIG. 5, in which the frusto-conical portion 20 is formed with a plurality of spaced annular grooves 26 which serve accurately to locate the filament loops about the rollers during the travel of the filament down the frusto-conical portions.

In still another embodiment of the invention, the frustoconical roller illustrated in FIG. 4 is replaced by a frustoconical roller as illustrated in FIG. 6, in which the peripheral surface of the roller is provided with regularly spaced annular grooves 26 enabling the filament to follow a carefully defined path in its passage from the feed end of the roller to the delivery end thereof, allowing accurate control of the relaxation of the filament.

What we claim as our invention and desire to secure by Letters Patent is:

1. Apparatus for heat treating a travelling filament or yarn, comprising two spaced driven rollers about which the filament to be treated is passed to form a succession of filament loops round the two rollers, said rollers having a feed end around which the first filament loop is passed and an opposed delivery end around which the last filament loop is passed, and said rollers tapering at least in part from said feed end towards said delivery end thereof so that the path length of the filament loop at the feed end of the rollers is greater than the path length of the filament loop at thedelivery end thereof, and heating means mounted between the rollers and within the filament loops, said heating means having opposed heating surfaces both situated respectively in the paths of movement of the loops at both sides of the rollers so that portions of the filament loops extending between the rollers on one side thereof contact a heating surface on one side of said heating means and portions of the filament loops extending between the rollers on the other side thereof contact an opposed heating surface on the other side of said heating means.

2. Apparatus according to claim 1, wherein each of the heating surfaces contacts each filament during the greater part of its travel from one roller to the other.

3. Apparatus according to claim 2, wherein said heating means has opposed ends respectively formed with recesses which respectively receive the two rollers.

4. Apparatus according to claim 1 wherein the filament-contacting region of each of said rollers comprises a portion of reducing diameter over which the filament loops are arranged to pass, the arrangement being such that the diameter of the reducing portion decreases in a direction from the feed end to the delivery end thereof.

5. Apparatus according to claim 4, wherein the portion of reducing diameter is frusto-conical.

6. Apparatus according to claim 5, wherein the frustoconical portion of each roller is located at or toward the feed end thereof and the remaining portion of the roller is cylindrical at or toward the delivery end thereof.

7. Apparatus according to claim 1 wherein the filament-contacting region of each of said rollers is frustoconical throughout, and the diameter of said region of the roller decreasing in a direction from the feed end to the delivery end thereof.

8. Apparatus according to claim 1 wherein the filament-contacting surfaces of the rollers are plain.

9. Apparatus according to claim 6, wherein the frustoconical surface of each roller is provided with a plurality of spaced circumferential grooves which accommodate the filament loops passing round the rollers.

References Cited UNITED STATES PATENTS 2,070,252 2/1937 Borner 34152 X 2,495,053 1/1950 Conaway et al. 34-152 X 2,622,182 12/1952 Forzley et a1 26O3 X 2,660,808 12/1953 Birmingham 34-153 2,965,368 12/1960 McIlvried 263-3 X 3,221,385 12/1965 Stanley 219-388 X JOHN J. CAMBY, Acting Primary Examiner. 

